PARACHUTE RIGGER HANDBOOK
 

  Note: Some manufacturers provide line measurements for their canopies in their owner’s manuals. If so, the rigger should thoroughly measure the control line assembly and compare the measurements against those in the manual. Over time and use, the control lines have a tendency to stretch and change dimensions. At the same time, the rigger needs to compare the right and left side assemblies against each other for any differences. It is not uncommon for the left and right control lines to be different lengths, having been changed to remove a slight turn or change the opening characteristics.

Figure A is a sample chart that the rigger can fill in to document the various dimensions needed to repair or replace control lines.

 

 

 

 

  1.0 DISASSEMBLY:

  1.1 After measuring the control lines, remove them from one side only. Leave the other side for a reference to check the new lines against both for measurements and construction.

  2.0 REASSEMBLY:

  2.1 Determine how many upper control lines there are on the canopy. Four is the most common and this procedure will use this number for the example. With four upper control lines, there are really two continuous lines forming the assembly. Each pair of upper lines is folded in the middle to form two legs of the upper assembly. Each line is therefore measured at twice the A dimension plus 12". If the upper control lines have different lengths, make sure to use the longest measurement to determine the cut length for A (Refer to Figure A).

  2.1.2 Using a finger-trapping needle or wire, finger-trap a loop at the center of each of the lines, so the result is a line with a loop at the center with two legs extending from it [Figure B]. The eye of the loop should be no more than .25" with the fingertrapped portion 1" long. Bar tack or zigzag the finger- trapped section.

  2.1.3 There are two types of lower control line configurations: a continuous line and a noncontinuous line. The continuous line is one piece with a brake loop finger-trapped into it at the proper location. The noncontinuous line consists of two pieces which form the upper lower and lower lower control line as well as the brake loop. The continuous line configuration is found primarily on the older generation main canopies and on many of today’s reserve canopies. The noncontinuous configuration is found on most of the modern main canopies due to the ease of replacement because of wear. Paragraphs 2.2 thru 2.2.3 will describe the continuous line design. Paragraphs 2.3 thru 2.3.11 will describe the noncontinuous method.

  2.2 CONTINUOUS LINE METHOD:

  2.2.1 Take a piece of line used for the lower control line and cut a line equal to the B dimension in Figure A plus 12". On this line, measure from one end 8" plus the C dimension from Figure A and mark at that location. This will be the bottom of the brake loop. Mark the brake loop location according to Figure C.

  2.2.2 Take another piece of the lower brake loop line approximately 12" long. Finger-trap the brake loop assembly according to Figure D. Make sure the ends are scissor cut and tapered. Bar tack or zigzag the assembly [Figure E].

  2.2.3 Measure and mark the C dimension from the bottom of the brake loop. Run the bitter end of the lower control line thru the eyes of two of the upper control lines and finger-trap the line back into itself [Figure F]. Adjust the finger-trap to allow for shrinkage. This completes the continuous line method of lower control line fabrication.

  2.3 NONCONTINUOUS LINE METHOD:

  2.3.1 Take a piece of line used for the lower control line and cut it at the C dimension from Figure A plus 12". Mark at 6" from one end and finger-trap a loop .5-1" long as per Figure G.

  2.3.2 Take a second piece of control line material and cut it to the D dimension from Figure A plus 12" additional. Mark at 6" from one end.

  2.3.3 Finger-trap this line thru the loop at the end of the upper lower control line. Make sure there is a minimum of 4" finger-trapped in the line and that the lower loop is tight against the upper loop.

  2.3.4 Bar tack or zigzag the finger-trapped portions to secure them [Figure H].

  2.3.5 Measure and mark the C dimension from the bottom of the brake loop. Run the bitter end of the lower control line thru the eyes of two of the upper control lines and finger-trap the line back into itself. Adjust the finger-trap to allow for shrinkage. This completes the noncontinuous line method of lower control line fabrication.

  2.3.6 Measure the upper control lines according to dimension A plus .5". If the upper control lines are of uneven dimensions, make sure that they are marked accordingly.

  2.3.7 Lay the canopy on the floor with the trailing edge flat and straight and the line attachment tabs exposed. Lay the upper control lines so that they run to the correct attachment points and route them through the tabs [Figure J].

  2.3.8 Make sure that the lines do not have a twist in them and finger-trap the lines back into themselves with a minimum of a 4" finger-trap. Leave the running ends exposed [Figure K]. Do not trim the excess line.

  2.3.9 Anchor the brake loop securely and apply tension through the complete control line assembly. Measure the dimension A plus B starting at the outside corner of the trailing edge. Adjust the tension of the finger-trap to allow for shrinkage. Pin the finger-trapped section with a marker flag [Figure L]. Repeat with each upper control line until complete.

  2.3.10 After setting the dimension for each upper control line, bar tack or zigzag each section. Trim the excess so that the end retreats into the line.

  2.3.11 Measure the dimension D on the lower control line to set the toggle location [Figure M]. If the canopy is on risers, route the lower control line thru the guide ring and tie the steering toggle in place.

  3.0 INSPECTION:

  3.1 Check finished dimensions against original dimensions according to Figure A.

  3.2 Check that all finger-trapped junctions are secured with either a bar tack or zigzag.

  3.3 Make sure that there are no twists in the lines.

  3.4 Check that the steering toggles (if used) are tied on securely.

 
 
 
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